Although on the surface it may not look like it, there’s a stark difference between ‘could you do this’ and ‘do this please’.

‘Could you do this ‘ is actually taking the person’s time and opinion into account. ‘Do this please’, being an imperative, doesn’t. So even though you are using what should be polite language with ‘please’, you can still sound bossy.

If you use this enough, you gain a reputation for being bossy, a reputation that can lead to disobedience on behalf of the people you are requesting do something. My advice is to avoid the imperative as much as you can, and show that you care enough to take the other person’s time and opinion into account.